Re: UAV AXN Floater adaption

Just thought you might be interested as you were getting the Floater, I believe.

Good stuff there!

Since the AXN is the entry-point for FPV, I'm trying to keep all the FPV stuff external on mine but that guy has some good ideas.

Re: UAV AXN Floater adaption

Posted: Fri Aug 12, 2011 6:42 pm

by Juanlargo

I flew my AXN Floater Jet last evening and was able to fly for at least 30 minutes with power off. I found a thermal just over a hill that was perfect. I could have kept it up longer but I just got tired...

As for FPV, I have a 700 mw 2.4 GHZ system but have been experimenting with a 1 watt 432 MHZ system. I am considering a 10 watt video transmitter and switching to an 8 foot telemaster with a Zenoa gasoline engine and possibly a small generator and regulator. With my lightest 2.4 GHZ FPV (camera, GPS, transmitter, and antennas) installed in my Sky Surfer I can only get about 15 minutes of flight time before the batteries are done for. I'm beginning to think that a much larger airframe might be the way to go.

Yes I have a ham license for 432 MHZ and yes I am an American. For those of you who hate us just remember that we drink more beer than you do, we can't be all bad....

Re: UAV AXN Floater adaption

Posted: Fri Aug 12, 2011 9:03 pm

by RCModelReviews

For the video signal, I'd go the hi-gain antenna way rather than simply hiking the power of your transmitter.

If you have a diversity switch and multiple receivers then it becomes a fairly simple job to cover the entire area you intend flying in (so as to avoid null points) and even a relatively low-power video transmitter can go a *long* way if you're using a 15-20dBi antenna on the receiver. Also, if you're intent on using 2.4GHz for your video, a directional receiver antenna will significantly reduce the amount of off-beam noise you are picking up.

In practical use, I'd expect (for example) to get at least 25Kms line of site using a 500mW 5.8GHz receiver and a reasonably hi-gain receiver antenna.

Re: UAV AXN Floater adaption

Posted: Sat Aug 13, 2011 12:02 am

by Juanlargo

RCModelReviews wrote:For the video signal, I'd go the hi-gain antenna way rather than simply hiking the power of your transmitter.

If you have a diversity switch and multiple receivers then it becomes a fairly simple job to cover the entire area you intend flying in (so as to avoid null points) and even a relatively low-power video transmitter can go a *long* way if you're using a 15-20dBi antenna on the receiver. Also, if you're intent on using 2.4GHz for your video, a directional receiver antenna will significantly reduce the amount of off-beam noise you are picking up.

In practical use, I'd expect (for example) to get at least 25Kms line of site using a 500mW 5.8GHz receiver and a reasonably hi-gain receiver antenna.

Well right now I am using a dual corner reflector setup but not diversity switched, I use a mini circuits combiner and a low gain, 6db MMic buffer to keep the loss to a minimum. I get roughly 12 dbd with thei setup and decent beam width. I have a 20 dbd parabolic antenna but the 3db beam witdth is only about 10 degrees and it gets hard to follow the plane.

My reason for wanting to go to 432 MHZ is twofold. First I have the components to build a high power transmitter and I also have 4 16 element yagis spaced at 1/2 wavelength but again, it's plane polarization and not diversity although that is not too hard to implement. The second reason is we want to be able to span 15 to twenty miles from the control site hence the larger airframe. It is going to be an interesting project and we are hoping to do the initial tests in North Las Vegas in the spring. the first round of testing will be to get the bugs out of the GPS system and the video interface and screen displays. After that we will take it out to the edge of visual range to see if we have enough data to fly it reliably. I may try the 2.4 GHZ system with one watt and several gain antennas at the receiving site just to see which one provides a better image. Certainly the less power we need the less weight and more fuel we can carry. I'll let you know how it works out.